To manufacture semiconductor devices, there has been employed the lithographic technique which comprises forming a resist film on a substrate such as silicone wafers and selectively irradiating the same with actinic beams such as UV rays, far UV rays, excimer laser, X-ray or electron beams, followed by the development, to thereby form a resist pattern on the substrate. The resists to be employed in the lithographic technique are appropriately selected from negative-type resists in which the parts unirradiated with the actinic beams are dissolved and removed in the step of the development and positive-type resists in which the irradiated parts are dissolved and removed in the step of the development depending on the purpose.
In the pattern making by the lithographic technique, however, it is known that the multiple interference of light arises in a resist film and thus the dimensional width of the resist pattern varies with a change in the resist film thickness. The term "multiple interference of light" means a phenomenon which arises when an incident light having a single wavelength on a resist film interferes with a light reflected from the substrate, thus causing a difference in the light energy absorbed in the thickness direction of the resist film. The unevenness in the resulting resist film affects the dimensional width of the resist pattern obtained after the development to deteriorate dimensional accuracy of the resist pattern. This problem becomes noticeable, in particular, in the formation of a fine resist pattern on a stepped substrate. When a resist is applied onto such a stepped substrate, the resist film becomes uneven correspondingly to the stepped parts to thereby deteriorate dimensional accuracy of the resist pattern. Accordingly, it has been required to develop a technique by which the problem of the interference of light can be overcome and a fine pattern can be formed at a high dimensional accuracy even on a stepped substrate.
To relieve the interference of light, there have been proposed methods for forming an antireflective coating film on a resist film. For example, JP-B-4-55323 and JP-A-3-222409 disclose methods for forming water-soluble resin films of polysiloxane, polyvinyl alcohol, etc., while JP-A-5-188598 proposes a method for forming an antireflective coating film by using a film-forming composition containing fluorine which is water-soluble and removable with water (the term "JP-A" as used herein means an "unexamined published Japanese patent application", while the term "JP-B" as used herein means an "examined Japanese patent publication"). Although the antireflective coating films formed by the former methods exhibit antireflective effects to a certain extent, the coating films thus formed are poor in uniformity and frequently show unevenness of coating. To solve this problem, coating solutions for forming antireflective coating films are applied in a large amount in the above-mentioned methods.
In the field of manufacturing semiconductor devices, it has been urgently required to lower the production cost and elevate the productivity, as well as to improve the technical problems associating with fine processing. However, coating solutions for forming antireflective coating films are used in a large amount in the methods for forming antireflective coating films proposed by the publications cited above, which results in an increase in the production cost. Thus, it has been strongly required to develop a coating solution for forming an antireflective coating film which makes it possible to form a uniform antireflective coating film showing no unevenness of coating or little surface discontinuity even in a small application dose.